1. Field of the Invention
The invention relates in general to traction elevator systems, and more specifically to arrangements for terminating the ropes of such systems.
2. Description of the Prior Art
In traction elevator systems in which one or both of the movable components are roped 2:1, the ropes which extend from the sheave carried by the 2:1 roped movable element are terminated in the overhead via a dead-end hitch plate. It is desirable to use a large plurality of relatively small diameter elevator wire ropes with the full or double wrap traction drive arrangement usually used with multiple roping arrangements, because they accommodate the 180.degree. bends better than a smaller number of larger diameter ropes. However, the more ropes that are used, the larger the fleet angle. This is due to the fact that each rope is terminated at the dead-end hitch plate in an adjustable shackle arrangement which includes compression springs disposed about a shackle rod. The rope terminations are thus more widely spaced than the rope grooves in the 2:1 sheave carried by the movable element. The fleet angle changes as the movable element travels between its travel limits, flexing and thus causing fatigue of each rope at the rope-socket interface, especially in the shackle arrangements of unit construction which include the rope socket as an integral, fixed part thereof. The changing fleet angle, which is in the axial direction, taken with respect to the axis of the 2:1 sheave, also causes groove erosion or wear and rope wear, as the rope axis is not aligned with the groove axis.